A round change should be fired whenever val check fails

[GalRogozinski]

A round change should be fired when processing a QBFT proposal message and failing on a value check

Originally posted by @GalRogozinski in #69 (review)

[dknopik]

Isn't this impossible with deterministic round timeouts? ssvlabs/ssv#1120

[GalRogozinski]

@dknopik
I don't know if "impossible" is the correct term here.
It is a change we are offering.
Still needs to be discussed of course